J & S Franklin Ltd2014-10-30 05:42:37

"A warmer climate, with its increased climate variability, will increase the risk of both floods and droughts" - IPCC Intergovernmental Panel on Climate Change

Humanity has always battled the elements in one form or another, but the sheer amount of fresh water melting into the seas from the ice caps and thawing permafrost have serious implications to millions of people worldwide.

As worldwide temperatures rise, the likelihood of precipitation falling as rain rather than snow increases, and that has a direct impact on our rivers and seas causing a knock on effect as rivers burst their banks from pure inundation of rainwater and sea storms and surges overwhelm low lying coastal areas.

Whatever the direct cause of the flooding, the effects are multiplied by the vulnerability of our critical infrastructure.

Lack of flood response plans, protecting our critical infrastructure can cause catastrophic results that can leave thousands homeless, without power, water or access to emergency services.

Also, the cost to a country is likely to be counted in millions in repair costs, insurance and lost revenues.
The most obvious form of protection would be to ensure that critical infrastructure, be that power plants, fresh water supplies, emergency services, telecommunication systems, etc are located away from flood plains, coasts, sea ways, and rivers. However this is not always practical, so the best protection is to use existing technology to provide flood defences to protect and secure these vital resources from the considerable damage that flood water can cause.
Obviously all critical infrastructures cannot be protected, all the time; however measures can be put in place to protect infrastructure on a speedy basis as and when a threat arises.

J&S Franklin have built upon their experience and successes of DefenCell MAC, a new range of geotextile lined welded mesh gabions used initially in a force protection role to provide ballistic protection, blast mitigation and HVM vehicle barriers, and adapted it to be used in an environmental flood protection role in a new product, DefenCell MAC FEâ„¢ Flood Fighting Barrier.

The system has recently undertaken testing with the US Army Corps of Engineers, Engineer Research and Development Center (ERDC) in Vicksburg, USA producing excellent results - "the fastest construction times" and "lowest seepage figures" of any product in its class.

Early in 2004, Congress tasked the U.S. Army Engineer Research and Development Center (ERDC) to "devise real-world testing procedures for "promising alternative flood-fighting technologies" Through the General Investigation Research and Development Program, ERDC conducted research and developed a laboratory procedure for the prototype testing of temporary barrier-type flood-fighting structures intended to increase levels of protection during floods.

Companies that manufacture Flood Barriers were invited to bring their product to the test facility, and set up using either their own staff, or ERDC staff, and once testing has commenced no adjustments to the structure is allowed.

The DefenCell MAC FEâ„¢ flood fighting barrier system for the purposes of this testing procedure consisted of a series of wire-mesh baskets (gabions) partially lined with a geotextile fabric. For the units tested, five baskets were connected together to form one unit. The wire mesh panels were joined together with wire coils, and multiple units were joined together just by dropping a metal pin through overlapping coils.

Installation of the roughly 84-ft 5-in.-long barrier took a crew of 4 men 16.1 man-hrs, including one man operating a small skid-steer loader to fill the units with sand.

Static water seepage rates at a basin depth of 1 ft, 2 ft, and 2.85 ft were 0.04, 0.08, and 0.13 gpm/ft, respectively.

The only damage during the debris impact test was two wires on the gabion slightly bent by the log impacts. There was no damage to the functionality or reliability of the barrier.

Disassembly and removal took 4 men 1 hr 2 min to remove the barrier, plus additional time to remove the plastic sheeting and haul out the sand, for a total of 5.9 man-hrs.

Compared to a sandbag barrier of similar height and length, the DefenCell MAC FEâ„¢ barrier took less than one-tenth as long to erect, two-thirds as long to remove, had lower seepage rates at all water levels, had less damage, and required no repairs.

This is the second DefenCell product to be tested at ERDC and the MAC FEâ„¢ joins the lightweight DC2 Barrier in the list of approved flood protection products.

Developing plans for critical infrastructure protection is imperative for the protection of our critical infrastructures from flooding.
In the UK, the National Grid now has a 1.7km mobile flood defence system in place which can be deployed to substations anywhere in the country within 12-24 hours and all new substations and gas compressor stations are designed to be resilient to a 1 in 1,000-year flood event. However, some fifty-seven substations in the UK were also identified as potentially vulnerable to flooding.
Flooding is identified as one of the ongoing and principal risks to the UK's critical infrastructure and a plan requires resources and procedures to be in place for the rapid response of robust and approved systems.
In 2012 a DefenCell Flood Wall System was deployed in Smithland Kentucky, USA, to save the town from an imminent record flood surge.

The town of just 400 estimated that they had just 75 hours to prepare for a record surge in river levels, and protect itself from the Ohio River.

"Based on (calculation) and communication with EOC (Louisville District Emergency Operations Center), we determined there was insufficient time to fill and place sandbags, and that the DefenCell Wall System was the best choice to stay in front of the rising water," geotechnical engineer Steven Shifflett said.

Within 24 hours of receiving a call, DefenCell delivered three miles of Flood Wall units that, once installed, would provide almost four feet of additional flood protection barrier to a key stretch of the levee in Smithland. As a testament to DefenCell's ease of use, within an hour of delivery to Smithland, small volunteer teams were able to start placing, connecting and filling, the DefenCell Flood Wall systems, and within the first three hours they achieved an installation rate of 20+ units per hour. In this short period they installed the equivalent to over 22,000 sandbags.

The DefenCell barriers remained solid throughout the surge and the town was saved from flooding.